More Insight on How Pollution Is Bad for Your Heart

You probably know that breathing in all those nasty particles from air pollution can raise your risk for cardiovascular disease, and now we've got a bit more information about how that happens: Exposure to high levels of traffic-related air pollution can actually change the structure and function of the right ventricle of your heart, according to a new study in the American Journal of Respiratory and Critical Care Medicine.

As it happens, there’s been quite a bit of research about how pollution affects the left side of your heart, but not so much on the right side. Quick anatomy and physiology lesson: “The left heart pumps blood to nearly your entire body, and it is a strong muscle to do that job,” study author Peter Leary, MD, of the University of Washington Division of Pulmonary and Critical Care Medicine, told SELF. “The right heart on the other hand only pumps blood to your lungs, which are built to allow blood to flow easily through them, so the right heart is a much weaker muscle. It was long thought that the right side of the heart was not particularly important, only slightly more functional than a passive conduit between the body’s veins and its lungs.”

So because the right heart has historically been the black sheep of the chest, scientists haven’t focused so much on it — until now. “Lung diseases that raise the resistance to blood flow through the lungs and put greater strain on the right heart, such as pulmonary hypertension, join other recent observations to highlight the importance of the right heart,” Dr. Leary says.

Dr. Leary’s new study found that people who had higher exposure to markers of traffic-related air pollution also had right hearts that appeared to be under greater stress — he and his team noted dilation of the heart and increases in right-heart muscle mass, among other indicators.

While further research will be needed to establish a cause, Dr. Leary speculates that the dilation and thickening in the right heart may be related to inflammation or irritation caused by air pollution exposure.